The patent application relates to an organometallic compound comprising a central transition metal atom and a ligand coordinated thereto having a heteroatomic ring structure, a process for its preparation and a process for polymerization of olefins by means of catalyst compositions including said organometallic compounds.
For single active site olefin polymerizations is traditionally used organometallic compounds wherein a central transition metal atom is coordinated by one or more aromatic rings and optionally other groups which may be organic or halide groups, preferably alkyl or chloride groups. The aromatic rings have xcfx80-electrons by which the coordination to the metal is completed. Five members for the ring are most often used, and then the compounds are many times named as metallocenes. These cyclopentadienyl groups can be substituted in many ways: carbon atoms of the ring are connected by one or more separate groups which may contain heteroatoms and/or they can form one or more other rings. Fused rings connected to the cyclopentadienyl ring may constitute even very complicated compound structures. The cyclopentadienyl ring or its replacement rings with their fused rings may contain in their ring structure one or more heteroatoms, too.
This application relates in particular to the heteroatomic ring structure. Characterizing for the structure is that a ligand of the central transition metal atom includes at least three nitrogen atoms and essentially three nitrogens of them are bonded to the same central carbon atom forming a structure wherein the carbon atom is surrounded in three directions by the three nitrogens.
The structure of the organometallic compound may preferably be presented by the formula (1)
LnMXmxe2x88x92nxe2x80x83xe2x80x83(1)
wherein at least one L denotes said ligand coordinated by a xcfx80-electron bond to M and includes a heterocyclic ring structure having at least two fused rings and at least three nitrogen atoms, three of them being connected to said same carbon atom, one of them being common for two rings and two of them being in separate rings, M is the central transition metal atom and belongs to Groups IV, V or VI of the Periodic Table of the Elements, X is an organic group or a halide coordinated to said central transition metal atom M, m signifies the coordination (ligand) number of said transition metal atom M, and n signifies an integer from 1 to m.
The ligand L, except one ligand according to the invention, may be also a cyclopentadienyl ring or its substituted derivative, or the ligand may be also a different kind of group, aromatic or not by its nature. Between the ligands can be a bridge group.
The inventional structure for the ligand (L) is preferably presented in the equation (2): 
where groups R1, R2, R3 and R4 are the same or different selected from the group of H, C1-C12 alkyl, alkenyl, aryl (phenyl preferable), alkylaryl, or the groups R1, R2, R3 and R4 may contain silicon atoms instead of one or more carbon atoms, preferably they are SiH3, SiH2R5, SiHR6R7, SiR8R9R10 groups where groups R5 to R10 are also the groups recited above. The substituent groups may be also a combination of several groups recited above. The R1 to R4 can be interconnected to another one to form bridged structures. In the presence of a base a balance exists in the formula (2) between two ionic isomeric structures which are presented in the right of the formula (2). L is preferably a triaza bicyclo alkenyl, more preferably a 1,5,7-triazabicyclodec-5-enyl, most preferably a 1,5,7-triaza{4.4.0}bicyclodec-5-enyl.
Several compounds according to the invention are recited in a list below and they can be prepared in a similar method using proper reagents instead of those used in the TAB preparation and in the preparation of the inventional metallocene compounds including the ligand.
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium trichloride (3)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium chloride (4)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride (5)
Tetracis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium trichloride (2)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium chloride
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium dichloride
Tetracis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium trichloride
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium chloride
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
Tetracis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium dichloride
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium chloride
(Dimethylamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride
(Diethylamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride
(Methyl-tertButyl-amine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride
(Dimethylamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium dichloride
(Diethylamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium dichloride
(Methyl-tertButyl-amine)-(1,5,7-triaza[4.4.0]bicyclo-deatomc-5-enyl)titanium dichloride
(Dimethylamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
(Diethylatamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
(Methyl-tertButyl-amine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
(Dimethylamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium chloride
(Diethylamine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium
(Methyl-tertButyl-amine)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium chloride
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium di(N,N-dimethylamide)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium (N,N-dimethylamide)
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium tri(N,N-dimethylamide)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium di(N,N-diethylamide)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium (N,N-diethylamide)
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium tri(,N-diethylamide)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium di(N,N-dimethylamide)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium (N,N-dimethylamide)
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium tri(N,N-diethylamide)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium di(N,N-diethylamide)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium (N,N-diethylamide)
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium tri(N,N-diethylamide)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium di(N,N-diethylamide)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium (N,N-dimethylamide)
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium tri(N,N-dimethylamide)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium di(N,N-diethylamide)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium (N,N-diethylamide)
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium tri(N,N-diethylamide)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium (N,N-dimethylamide)
(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium di(N,N-dimethylamide)
Bis(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium (N,N-diethylamide)
Tris(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium
(1,5,7-triaza[4.4.]bicyclo-dec-5-enyl)chromium di(N,N-diethylamide)
(Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride
(n-Butyl-Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride
(Indenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride
(Fluorenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)zirconium dichloride
(Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium dichloride
(n-Butyl-Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium dichloride
(Indenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium dichloride
(Fluorenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)titanium dichloride
(Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
(n-Butyl-Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
(Indenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
(Fluorenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)hafnium dichloride
(Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium chloride
(n-Butyl-Cyclopentadienyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium chloride
(Indenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium chloride
(Fluorenyl)-(1,5,7-triaza[4.4.0]bicyclo-dec-5-enyl)chromium chloride
The invention also relates to a method to prepare an organometallic compound comprising a central transition metal and a ligand coordinated thereto having a heteroatomic ring structure. The compound consisting of the ligand which includes at least three nitrogen atoms, three of them being bonded to the same carbon atom, and a hydrogen atom bound to one of said three nitrogen atoms of said ligand, is reacted with a metallocene and/or a halide of said transition metal. Preferably, an alkaline metal salt of the ligand is reacted with a transition metal halide, preferably chloride. According to an embodiment, the ligand is prepared as follows: first a salt of an alkaline metal of toluene is produced, and the salt is then reacted in toluene solution with said compound consisting of the ligand and a hydrogen atom bound to one of its three nitrogen atoms. The alkaline metal is preferably potassium.
The organometallic compounds according to this invention can be used in olefin polymerizations. Olefin monomer can be polymerized alone or with one more olefins and/or with other monomers. Preferable olefins are alfa-olefins, and most preferable is ethylene: homo or copolymers of ethylene are produced in huge amounts that the catalysts suitable to this kind of applications can be very valuable.
The organometallic compounds alone are usually not at all or only slightly active in polymerization reactions. The activity can be increased remarkably by using with them one or more cocatalysts which activates the organometallic to a suitable constitution to be able to catalyze the polymerization reaction. The most common cocatalyst in the art is methyl aluminoxane (MAO) which can appear in linear, cyclic or polymerized form. Formulas of different isomeric forms of aluminoxanes can be seen for instance in patent application FI 972230, which is herewith included as a reference.
Higher aluminoxanes having more than one carbon atoms in the alkyl group, e.g. 2 to 10 carbon atoms can be used. Also other kind of compounds than aluminoxane can be used although not often used in commercial scale. In this sense particularly boron compounds, e.g. boranes seem to be very interesting.